III.
CHARACTER OF VEGETATION.
This chapter I begin with a phyto-geographical classification given by Dr. Carl Hoffman and published in Bonplandia in 1858. He distinguishes:
First.—Coast regions (sea shores and salt swamps).
Second.—Regions of tropical forests and savannas, stretching from the coast regions to a height of 900 meters.
Third.—Regions of high plains, lying between 900 to 1500 meters of elevation.
Fourth.—Region of upper tropical forests, situated between 1500 to 2150 meters of altitude.
Fifth.—Region of oaks, from 2150 to 2750 meters in height.
Sixth.—Region of chaparrales, from 2750 to 3050 meters up.
Seventh.—Region of subalpine or subandine flora, from 3050 meters up to the tops of the high mountains.
Dr. Polakowsky enumerates cultivated lands, virgin forests, open forests and savannas.
Another division is given by Dr. Moritz Wagner. He mentions a littoral (as appears on next page) zone, a tropical forest zone and a zone of savannas.
He also distinguishes on the volcano of Chiriqui the following successive regions:
First.—Regions of evergreen forest trees and palms, bananas, Araceæ, etc., to a height of 550 meters, with an average temperature of 26° to 24° C.
Second.—Region of tree ferns and mountain orchids, from 550 to 1220 meters, with an average temperature of 23° to 18° C.
Third.—Region of Rosaceæ, Senecionodeæ, Gramineæ and Agave americana, from 1220 to 1585 meters.
Fourth.—Region of Cupuliferæ and Betulaceæ, mostly oaks and alders, from 1585 to 3050 meters.
Fifth.—Higher region above 3050 meters.
Dr. Wagner calls special attention to a noted uniformity of the flora on the coasts of both oceans, and Professor Pittier affirms that the vegetation between Colon and Greytown on one side, and between Panama and San Juan del Sur on the other side, is remarkably uniform. The littoral zone has a width of about four maritime miles. The predominating flora is composed of Rhizophora mangle, Hippomane mancinella, Cocos nucifera, Chrysobalanus icaco, Crescentia cujete, Acacia spadicigera, Cæsalpinia bonducella and other Leguminosæ; Acrostichum aureum, Ipomœa pescapræ, Avicennia nitida, Uniola Pittierii and also Euphorbiaceæ, etc.
The zone of tropical forests shows, especially on the Atlantic side behind the coast region, a strip of from twenty to twenty-two miles in width, with lofty trees of Rubiaceæ, Myrtaceæ, Melastomaceæ, Sterculiaceæ, Euphorbiaceæ, Meliaceæ, Urticaceæ, Moraceæ, Anacardiacæ, Sapindaceæ, Leguminosæ and Palmæ. It is relatively free from ligneous undergrowth, having more monocotyledonous plants, such as Cycadeæ, Scitamineæ, Cannaceæ, Marantaceæ, Cyperaceæ, Filices and Bromeliaceæ, underneath. The latter orders figure, also with Orchideæ and Loranthaceæ among the epiphytes and parasites which cover the trees. Among the most characteristic plants of this region we name the coyol palm (Acrocomia), corozo (Attalea cohune), biscoyol (Bactris horrida), palmiche (Elæis melanococca) and Raphia nicaraguensis which forms almost forests along the River San Juan; further, Tecoma pentaphylla, Bombax ceiba, Eriodendron, Spondias, Croton gossypifolius, Hymenæa courbaril, rubber trees (Castilloa costaricencis and C. elastica), Geoffræa superba, Simaba cedron, species of Enterolobium, Cæsalpinia, Liquidambar, Copaifera, Cedrela, Swietenia, Sapota, Pithecolobium, Palicourea, Cinchona, Piper, Ficus, Cecropia; still further, smilax, vanilla, etc. Many of these characteristic plants are largely social, such as the piper, ferns, palms and others.
Moritz Wagner states that all along the southern limits of Costa Rica a likeness of climatic and geological conditions gives to the vegetation a nearly uniform character, while further northward a notable contrast is observed between the Atlantic and Pacific slopes of the mountain groups and on the interior terrace lands. The Atlantic slope, with more constant humidity of air, is characterized by vast, dense, evergreen, virgin forests, while the Pacific lands, with a relatively dry climate and rainless summer, present more open forests and savannas, with many deciduous trees and shrubs. However, deep river valleys and some slopes near the water-shed have dense, evergreen forests, and their vegetation does not differ much from that of the Atlantic slope. The flora of the high terrace lands has been so altered by thorough cultivation as to have almost lost its original character.
The Atlantic virgin forests, as well as those in the region of the San Juan River and of Lake Nicaragua, which comprise two-thirds of Costa Rican territory, show such a dense vegetation that its interior can be penetrated almost only by way of the rivers, and its general character and its enormous extension be studied only from high mountains. Owing to the very mountainous character of the country, over half of its area lies between 900 and 2100 meters above the sea, and is almost wholly covered with virgin forest. This forest here and there ascends still higher, reaching the upper limit of the oak region about 2700 meters above the sea.
Dr. Polakowsky, in an interesting publication entitled “Flora of Costa Rica,” calls the forest region of the San Juan River, in view of its luxuriant character, “The Central American Hylæa,” and this name Professor Pittier applies also to the entire Atlantic region, attributing to it a distinctly South American character.
The zone of the open forests and savannas, which has park-like features, is rarely found away from the Pacific side, where it forms a belt from sixteen to eighteen miles in width, interspersed with more densely forested river valleys, islands of higher and thicker virgin forests, isolated trees or groups of trees, sometimes also with catingas and meadows flecked with shrubs and matorrales.
The savannas and open forests spread to a considerable extent over Guanacaste, where they are a continuation of those of Rivas in Nicaragua; also over the plains of Terraba, especially in the region of Buenos Aires and Terraba; and over the coast-lands of Golfo Dulce. There are some small similar tracts near Alajuela, Turialba, Santa Clara and at some other points, as well as catingas and paramos in the high mountain ridges of the south. The paramos are found on poor soil and have a vegetation more herbaceous than ligneous, which, when moist, takes on the character of turf.
The trees of the savannas are generally of little height, excepting the Enterolobium cyclocarpum (the guanacaste), the pochote and ceiba. The grass lands are almost wholly composed of Gramineæ and Cyperaceæ, especially in the savannas of Guanacaste. The most characteristic plants are Digitaria marginata and Paspalum notatum, besides species of Setaria, Panicum, Eragrostis, Andropogon, Isolepis, Cyperus, Rhynchospora and Scleria, as well as of ferns (Pteris aquilina) and Schizæa occidentalis.
Other abundant plants in the open forests and savannas are Compositæ (Zemenia, Pectis, Spilanthes); Rubiaceæ (Spermacoce); Polygalaceæ; Iridaceæ; Moraceæ (Maclura, Ficus); Melastomaceæ (Miconia, Clidemia, Conostegia, Leandra); Cyperaceæ; Convolvulaceæ; Euphorbiaceæ; Bombacaceæ; Sauvagesia. Further, Myrtaceæ (Psidium, Alibertia edulis); Curatella americana (chamico); Roupala (danto hedliondo); Byrsonima crassifolia (nance); Miconia argentea DC. (santa maria); guacimo macho (Luhea), guacimo de ternero (Guazuma ulmifolia); burio (Bombax apeiba); ñambar (Cocobola); Davilla lucida; Duranta Plumieri; Proteaceæ; and Acacia scleroxyla Lonchocarpus atropurpureus, Dalbergia and many other Leguminosæ, especially Mimosa pudica, which gives large tracts in many places a special character, and still more so as, being often very abundant and the plants tangled together, a general movement all around is caused when one is touched.
Among the epiphytes and parasites may be mentioned small ferns, Peperomia, Epidendrum, Loranthus, Aroideæ, Tillandsia and other Bromeliaceæ, mosses, lichens, etc.
Professor Pittier attributes to this flora of the Pacific slope a more northern origin.
During the dry season the vegetation of the savannas almost disappears, the greater part of the trees and bushes shed their leaves and herbs become dry and brittle. Only along the rivers is some freshness observable. Toward the border of Nicaragua cacti appear, mostly species of Cereus, Opuntia, Phypsalis and Mammilaria. Professor Pittier also mentions an oak forest of Quercus citrifolia between Liberia and the Rio de los Ahogados, at a height of about one hundred meters above the sea. The peninsula of Nicoya is noted for a large lumber industry among its different cedars (Cedro dulce, C. amargo, C. real, etc.), mora and other trees. Towards the upper limits of the Atlantic tropical forests, below the oak region, Chamædorea, Geonoma, Bactris, Euterpe longepetiolata and other palms of the same groups, as well as Gulielma utilis (the pijivalle palm) and Carludovica microphylla are seen in great abundance, mixed with tree ferns like Alsophylla pruinata, Hemitelia horrida, Hemitelia grandifolia, etc. Higher up appears the region of oaks, principally Quercus retusa, Quercus granulata, Quercus citrifolia and Quercus costaricensis, with Buddleia alpina, Rubus, Lupinus, etc. Here is also the region of the common potato. This oak region slopes gradually down from east to west. The vegetation on the summits of the high mountains of Costa Rica is of a marked subalpine character, having a great number of northern genera, as Vaccinium, Pernettya, Alchemilla, Cardamine, Calceolaria, Spiræa, etc.
Certain types of vegetation are often more due to the sterile nature of the soil than to elevation.
Although a northern flora is frequent on the high terraces of San José and Cartago, that character is not general because of the introduction of cultivated tropical and other plants peculiar to Costa Rica.
On the southern high mountains two species of Podocarpus (P. taxifolia and P. salicifolia), one of Alnus (Alnus Mirbelii Spach.) and one of Weinmannia occur quite generally among the oak forests. Other distinct floral groups are represented by the vegetation along roads and fences, on potreros, in cultivated regions and along river shores. The latter especially are rich in herbaceous plants, grasses, bushes and woods of Bignoniaceæ, Myrtaceæ, Euphorbiaceæ, Mimoseæ, etc.
The potreros are characterized by Tagetes, Sida, Hyptis, olanum, Salvia, Mimosa pudica and M. sensitiva, etc. Along fences there grow nearly everywhere Erythrina corallodendron, Yucca aloifolia, Bromelia pinguin, Agave americana, Cereus, Spondias, Bursera, Cestrum, etc.
Prominent characteristic plants, besides the already mentioned species and genera, are the Piperaceæ and Melastomaceæ; further, species of Iriartea, Bactris and Raphia of the palm order, and Alsophylla, Schizæa occidentalis and Pteris aquilina of the ferns; still further Castilloa costaricana, Gunnera insignis, Ochroma lagopus, Gliciridia, Inga edulis, Chusquea maurofernandeziana, Erythrina corallodendron, Drymis Winterii Forst., Acacia Farnesiana, etc.
The passage from one flora to another is one of insensible gradations. Cultivated lands, as already stated, do not show any longer the original vegetation.
The plants which are now mostly cultivated are: Coffea arabica (coffee), Saccharum officinarum (sugar cane), Zea mays (corn), Musa paradisiaca and Musa sapientium (bananas), Phaseolus (beans), Oryza sativa (rice), Solanum tuberosum (potato), Nicotiana tabacum (tobacco), Batatas dulcis (sweet potato), Lycopersicum esculentum and Lycopersicum Humboldtii (tomatoes), Capsicum annuum (chile), Ananas sativa (pine-apple), Carica papaya (papaya), Persea gratissima (aguacate), Anona cherimolia (cherimoya), Manihot aipi and Manihot utilissima (yucca or mandioca), Indigofera anil (indigo), Gossypium barbadense (cotton), Cichorium Intyous (chicory), Asparagus officinalis (asparagus), Psidium guava (guayaba), Mammea americana (mamey), Theobroma cacao (cacao), etc.
Before giving the lists of the woods, tannings, dyeings, gums, balsams, resins, rubber, waxes, textile and medicinal plants, oils and oil seeds, etc., of Costa Rica, it is advantageous to research to name those collectors and scientists who, having traveled through Costa Rica or established themselves there, have especially contributed to the knowledge of the natural resources of the country. They are Professor H. Pittier, A. S. Oersted, Dr. C. Hoffmann, Dr. H. Polakowsky, Dr. M. Wagner, Captain J. Donnel Smith, C. Warszewicz, Neudland, A. Tonduz, P. Biolley, Dr. A. von Frantzius, Dr. Franc Kuntze, Professor W. M. Gabb, José C. Zeledón, Anastasio Alfaro, Juan J. Cooper, and Bishop Bernardo Augusto Thiel, D. D.